Search results

The Yaesu FL2100Z is a HF linear amplifier rated for 1200W PEP input, and using two 572B triode tubes. This article explores the recommended operating conditions, and alternatives.

Repairt a Heathkit SB-220 Linear Amplifier with a bad Plate Voltage meter

Article about assembling of a Dick Smith Electronics (DSE) 100 Watt VHF Linear Amplifier kit.

QST Magazine Product Reviews - Key Measurements Summary - HF-Transceivers or Receiver and Linear Amplifiers

Pictures of a monoband linear amplifier for 40m band - 2 x QB5/1750 made by 9A6A

TSC International produces soft magnetic sheet steel, custom-stamped and heat-treated to achieve optimal electrical characteristics for applications such as motors, generators, linear power supplies, and ballasts. The company's manufacturing process focuses on precise material engineering to meet specific performance requirements in various electrical systems. They also specialize in soft magnetic core materials essential for transformers, chokes, and inductors. These core materials are utilized in power supplies, lighting ballasts, signal conditioning circuits, inverters, and battery chargers, providing critical magnetic properties for efficient energy conversion and signal integrity. Located at 39105 Magnetics Blvd, Wadsworth, IL 60083-0399, TSC International provides contact via sales@tscinternational.com or phone at +1 (0) 847 249 4900, facilitating direct inquiries regarding their magnetic component offerings.

Understanding Solid State Linear Amplifiers

Collection of Kenwood TL-922 linear amplifier modifications

eHam reviews for the Ameritron AL-811 linear amplifier

A 160W linear amplifier for 4 meters band based on GI0GDP

A lot of good things, not for QRP fans.

A 600W 1.8 MHz to 54 MHz power linear amplifier made using rugged MRF300 transistors featuring output power between 580W and 750W depending on band, power supply: 48V, 18A typical, 20A max

HF Linear Amplifiers, maker of the HAL600 Atlantic atomatic HF Amplifier

A home made 50 MHz KW power amplifier project with picture and PCB schematic by W6PQL

Linear amplifiers cold adjustments with network analyser (VNA)

Yaesu FL-110 160-10m HF linear ampflifier as ideal power amp for the FT-817 by N2CHK

Pictures of a homemade monoband linear amplifier for 160m band powered by 3 x QB5/1750

222 MHz kilowatt linear amplifier

Icom PW1 Linear Amplifier, setup and configuration PDF file

The N1HFX thermal cooling fan controller project details a practical circuit designed to manage cooling fan operation based on temperature, a common requirement for high-power amateur radio equipment. This build utilizes a **LM34** temperature sensor, providing a linear voltage output directly proportional to Fahrenheit degrees, simplifying the control logic. The circuit's core functionality involves a comparator that activates the fan when a preset temperature threshold is exceeded, ensuring efficient cooling and reducing unnecessary fan noise. This controller is particularly useful for amplifiers, power supplies, or transceivers that generate significant heat during operation. The design incorporates a _TIP120 Darlington transistor_ to drive the fan, capable of handling up to 5 amps, making it suitable for a range of fan sizes and current requirements. Field results indicate stable temperature regulation, preventing thermal runaway in enclosed environments. Construction involves readily available components, making it an accessible project for hams looking to optimize their station's thermal management.

RF amplifier products from NP Technologies, Inc. encompass a wide array of specialized designs, including highly linear Class A broadband amplifiers, crucial for maintaining signal integrity across various frequencies. Their portfolio also features cell band amplifiers, specifically engineered for cellular communication infrastructure, and pulse amplifiers, which are vital in applications requiring high-power, short-duration signal bursts. The company's manufacturing capabilities extend to AM and FM broadcast amplifiers, supporting radio transmission systems, and military VHF amplifiers, designed to meet rigorous defense specifications for robust and reliable communications. NP Technologies, Inc. emphasizes comprehensive development, design, manufacturing, and testing processes for all its RF amplifier offerings. This integrated approach ensures that each product, from initial concept to final deployment, adheres to stringent performance and reliability standards. The company's expertise in these areas allows for the creation of custom solutions tailored to specific client requirements, addressing complex RF challenges in diverse operational environments. Their product range demonstrates a commitment to serving multiple sectors, including commercial broadcasting, telecommunications, and defense. The focus on specialized amplifier types underscores their technical depth in RF engineering.

Demonstrates the construction of a high-power 6-meter (50 MHz) amplifier, specifically designed for demanding modes like EME, TEP, and multiskip Es. It details the use of a _GU-43B_ tetrode in a grounded-cathode configuration, emphasizing the need for stabilized grid voltage and input capacitance compensation. The resource provides a comprehensive schematic, power supply design, and practical considerations for component sourcing, particularly for high-voltage and high-current sections. The builder achieved an output power of **1250 watts** with an anode current of 0.65 amperes and 3200 volts anode voltage. The article also covers the physical construction within a modified P6-31 enclosure, outlining the internal layout for RF and power supply sections, and includes photos of the completed unit. It highlights critical safety precautions for working with high voltages and reactive currents up to **20 Amperes** in the P-network.

Makers of the worlds smallest automatic solid state HF amplifier Expert 1K-FA, Expert 2K-FA and Expert 1.3K-FA

Design, develop, test and manufacture a wide range of Amplifier products including highly linear class A Broad Band, Cell Band, Pulse, AM & FM broadcast and Military VHF

The MiniPA Linear Amplifier for HF page discusses the popularity of QRP for HF among ham radio operators, such as those using the Yaesu FT818 or low power SDR transceivers. It explores the use of cheap kits from eBay or Chinese suppliers to build a 70-100W SSB amplifier using IRF530 MOSFET transistors. The article provides a review of the MiniPA design, including its features, components, and assembly process. It also highlights the importance of using a heatsink and forced air cooling for optimal performance. This page is useful for hams looking to enhance their HF rig with a budget-friendly amplifier.

Icom PW-1 1kw Linear Amplifier described by WA0SXV

This page details my building of a 100 Watt Power Amplifier for the 432 MHz Band based on two Motorola MRF646 transistors taking inspiration by Carlo Gnaccarini VK3PY, formerly VK3BRZ

The Icom IC-PW1 is a 1000 watt linear amplifier with built-in power supply

TFilter is a free online tool for designing linear phase, optimal, equiripple finite impulse response (FIR) digital filters. It utilizes the Parks-McClellan algorithm implemented in JavaScript. Users can specify the sampling frequency, desired number of taps, passbands, and stopbands to generate a filter. An example configuration is provided for easy testing.

The RM Italy HLA 300 linear HF amplifier, a solid-state unit designed for 12-14 V operation, is examined through practical experiences and test results. This survey highlights key operational aspects, including the necessity of the ventilated 'V' version for effective cooling, which operates quietly on standby and engages immediately on transmit. Manufacturer specifications claim 300 W CW output with 1-15 W input and 550 W SSB output with 2-20 W input, making it a robust option for many HF operators. PH4U/DC2DC's field tests on his HLA 300, an all-band/all-mode transistor amplifier drawing 45 A, provided valuable insights into its real-world performance. The amplifier features six low-pass filters, covering nine HF bands, a notable inclusion compared to many similar products. Testing revealed that a 1-Volt drop in the 12-14V supply, common with high currents (45-55 Amps) and inadequate cabling, can significantly impact output power, with a 50 W increase observed when voltage rose from 12 V to 13 V under load. Observations also noted that driving the HLA 300 with only 5 W, such as from an FT-817, is insufficient to reach its full potential, suggesting an intermediate amplifier stage is needed to achieve the recommended 20 W input. Modifications, such as removing a 100 pF capacitor, improved performance, and replacing output transformers with BN43-7051 (mix 43) ferrites significantly reduced distortion, as evidenced by spectrum analyzer images from PA1HR's HLA 150 modification.

A simple 2-tone-generator for testing the linearity of SSB transmitters. This device is as simple as useful. With 2 transistors and an oscilloscope, it is fairly easy to test the linearity of your SSB transmitter. The 2-tone-method is a standardized test method that can be used to determine the maximum output and the amplification characteristics of a sideband transmitter.

This is a power amplifier project for a RF 600W 1.8 MHz to 70 MHz linear amplifier including a Low Pass Filter. Projects includes schematics, pictures, PCD design, fans details, note on PA ferrite chokes and assembling instructions

JBOT stands for Just a Bunch of Transistors. It is a simple, stable and easy to build 5 watts linear amplifier build out of a bunch of ordinary low power NPN transistors.

This article details the design and construction of a compact 20-meter QRP SSB transceiver by Pete Juliano, N6QW, measuring just 2 x 4 x 2 inches—small enough for a shirt pocket. Inspired by a 1963 QST design and refined from a prior version, it employs bilateral circuits, a 4.9152 MHz homebrew crystal filter, switched-crystal VXO for 60 kHz coverage (14.160-14.220 MHz), and standard components like ADE-1L mixers and IRF510 PA for 1W output. Key innovations include a double-sided PCB skeletal frame for shielding and isolation, Vectorboard sub-assemblies, and ultra-miniature relays. The bilateral receiver/transmitter shares stages, omitting AGC for simplicity, while a W3NQN LPF and optional 10W external amp enable DX contacts. Tune-up focuses on crystal matching and bias for linearity. Videos on YouTube demonstrate performance, confirming excellent stability and audio. Total cost nears $100, prioritizing portability over features like CW.

Demonstrates ZeusSDR, a WebGL-native station console for _OpenHPSDR_ radios, including Hermes-Lite 2 and ANAN-class transceivers. The software integrates a 2D and 3D WebGL/WebGPU panadapter with click-to-tune functionality, alongside native FT8/FT4 and FreeDV digital voice modes, eliminating the need for external software like WSJT-X or virtual audio cables. It features a protected transmit chain with SWR-trip and TX-timeout, and supports _PureSignal_ linearization on Protocol 2 for enhanced signal quality. The console incorporates a broadcast TX chain with a noise gate, 10-band EQ, compressor, exciter, bass, reverb, and VST3/Audio Unit hosting for advanced audio processing. A comprehensive logbook is included, offering contact history, a 3D NASA globe, DX radar, and analytics for DXCC/WAS/grids, with ADIF and LoTW integration. Amplifier panels for RF2K-S, KPA500, and SPE Taurus are also provided. ZeusSDR supports both OpenHPSDR protocols (P1 + P2) and utilizes WDSP from Thetis. It is available for Windows, macOS, and Linux, with a public listening feature allowing others to view live waterfalls and use virtual receivers with Zeus DSP, including NR, NB, ANF, AGC, and filters. The software is open-engine, following the PowerSDR–OpenHPSDR–Thetis lineage.

The Acom 1500 HF+6M Linear Amplifier is a high-quality and user-friendly amplifier that provides excellent performance and reliability. G6NHU, who previously owned an Acom 1000, upgraded to the Acom 1500 after nine years and has been using it for about eighteen months. Key features highlighted include the ability to connect three antennas internally, straightforward tuning process, robust construction that can handle high SWR, quiet operation, fast and quiet switching for efficient CW operation, and clean output signal even when driven hard. G6NHU highly recommends the Acom 1500 and states they would not hesitate to purchase another one in the future.

The Olivia digital mode, a **Multi-Frequency Shift Keying (MFSK)** radioteletype protocol, is specifically engineered for robust communication under difficult propagation conditions on shortwave radio bands from 3 MHz to 30 MHz. Developed by Pawel Jalocha in 2003, Olivia signals can be decoded even when the noise amplitude exceeds the digital signal by over ten times, making it highly effective for transmitting ASCII characters across noisy channels with significant fading and propagation phasing. Early on-the-air tests by Fred OH/DK4ZC and Les VK2DSG on the Europe-Australia 20-meter path demonstrated intercontinental contacts with as little as one-watt RF power under favorable conditions. Common Olivia modes are designated as X/Y, where X represents the number of tones and Y is the bandwidth in Hertz, with examples including 8/250, 16/500, and 32/1000. The resource clarifies that Olivia, unlike some other digital modes, produces a constant envelope, allowing RF power amplifiers to achieve greater conversion efficiencies and making it less prone to non-linearity. Operators are advised that **Automatic Level Control (ALC)** can be set higher than no meter movement for MFSK modulation, as long as it's not driven past its high limit, contrary to common misinformation about other digital modes. The Olivia community encourages voluntary channelization on suggested calling frequencies, such as 14.0725 MHz for 8/250, to facilitate initial contacts, especially for signals below the noise floor. The Olivia Digital DXers Club provides links to Groups.io, Facebook, and Discord for community engagement and offers details on QSO parties.

The Yaesu FTDX10 MF/HF and 6-meter transceiver, a 100-watt rig, is designed to bring high-performance receiver architecture to the intermediate-price class. It offers continuous receive coverage from 30 kHz to 75 MHz and transmit capabilities across all amateur bands from 160 through 6 meters, including five preset CW and SSB channels on 60 meters. The transceiver supports AM, FM, SSB, CW, and digital modes, with integrated decoders for CW, RTTY, and PSK31, making it a versatile station for various operating preferences. Physically, the FTDX10 measures 3½ × 10½ × 10½ inches and weighs 13 pounds, requiring a 20–25 A DC power supply for full 100 W output. Its front panel features a 5-inch TFT color touchscreen and a large VFO knob, complemented by an SD memory card slot for recording audio and saving settings. Rear panel connectivity includes a single SO-239 antenna port, multiple USB ports for CAT control and peripherals, and DIN jacks for external digital mode hardware and linear amplifiers, though it lacks a dedicated low-noise receive antenna provision. ARRL Lab tests confirm excellent receiver performance, with blocking dynamic range exceeding 137 dB at 2 kHz spacing and robust IMD dynamic range figures. The hybrid receiver design incorporates selectable roofing filters at 500 Hz, 3 kHz, and 12 kHz, along with two preamplifiers and various attenuation levels, allowing operators to tailor reception characteristics to challenging band conditions. Transmitter performance is also rated very good, with low transmit phase noise.